The distal end of a cardiac catheter is usually attached to the cardiac wall by a barbed or screw-type catching device to maintain the stimulation and detection electrodes against the cardiac wall. The electrodes are usually disc or ring-shaped, in order to have as much of their area as possible in contact with the cardiac wall. In certain applications, the detection electrodes are separate from the stimulation electrodes and are not in contact with the cardiac wall.
In U.S. Pat. No. 4,365,639, the detection electrodes are arranged on the lateral surface of the catheter, away from the stimulation electrode. In European patent No. 0,191,238, the stimulation electrode is disc-shaped and the detection electrodes are in the shape of a rod having a spherical end that is applied to the cardiac wall via an opening in the stimulation electrode.
In each of the two previous cases, the distal end part of the cardiac probe is practically rigid. In securing the probe to the cardiac wall, the objective is to ensure good contact between the stimulation electrode and the cardiac wall. It is for this reason that the probe is attached efficiently, i.e., traumatically. However, the creation of fibrin and the lesion of the cardiac wall, which modifies the cells, entail a degradation of the stimulation and of the detection. This phenomenon is aggravated by the efforts transmitted by the catheter to the attachment during heartbeats. For instance, the screw-type probe in European patent No. 0,191,238 creates a major lesion.